A sample letter: Prague, the night the season turns
What a letter from your sky looks like, made in full for a real place and a real night: Prague, from the Old Town Square, on the night of 22-23 September 2026, when the autumn equinox falls just after two in the morning. Every hour and direction below was computed for that square before it was written.
Prague,
You asked for the turning night. Here is the sky that will stand over your roofs, checked to the hour.
The good dark begins at 19:40, and your best hour is the first one, because one of my five is already leaving. The equinox itself falls at 02:05, while you sleep: the sun crosses the celestial equator and the season turns.
Vega is the first and the easiest. Soon after dark it stands seventy-nine degrees up, nearly overhead, a little to the south: the brightest light of your upper sky, and one that survives the city's glow. Find it as the top corner of the Summer Triangle. Its companions are Deneb, almost straight overhead at 21:40, and Altair, halfway up the southern sky at ten to nine.
Arcturus burns low in the west, fire-coloured, and does not wait: it is gone before half past ten. Find the Big Dipper first: low in the northwest, bowl toward the north, handle swinging west. The two outer stars of the bowl aim up at Polaris; follow the handle's curve down and on, and it lands on Arcturus. If trees or rooftops hide the Dipper, simply look west early: one bright fire-coloured point, low, alone.
Polaris never leaves you: due north, fifty degrees above the horizon, the one light that does not turn while all the others do. It holds only on a truly dark street, and the Dipper's two pointers will take you to it.
Deneb and Altair complete the Triangle, and both want a darker street: Deneb is the hen's tail, the old Arabic said, and it passes almost exactly overhead at 21:40; Altair is the lowest corner of the three, in the south.
A word about the moon, so you know what sky you are getting: a waxing moon, four nights short of full, low in the southern sky through the evening. It will silver the rooftops until about three, and it will leave the high stars alone.
The old names, kept: Vega is an-nasr al-waqi, the swooping eagle; Arcturus is Arktouros, the guardian of the bear. Your Old Town Hall has kept an astronomical clock since 1410. The five lights it answers to are far older, and on this night they keep their places.
If you go out on the turning night and one of them finds you, I would be glad to hear which.
Aelthir
The working, for anyone who wants it: the positions come from catalogue data, the hours and directions were computed for 50.0876 N, 14.4212 E, and the dark window and the equinox from a real ephemeris. Nothing here is invented, including what is missing.
For a letter like this for your own place: name a place and a night. The first light is free; the full letter is $25, agreed before anything begins. Write to me: [email protected]